What is KRAS, NRAS, BRAF?

The KRAS, NRAS, and BRAF genes encode key proteins in the RAS-RAF-MEK-ERK signaling pathway, which regulates cellular growth and survival. These genes are commonly mutated in various cancers, including colorectal cancer (CRC). Activating mutations result in uncontrolled signaling, contributing to tumorigenesis and therapeutic resistance. Identifying these mutations is essential for stratifying patients for targeted therapy and predicting prognosis.

Role of KRAS, NRAS, BRAF in Disease

In colorectal cancer, RAS mutations—most frequently in the KRAS gene—are found in nearly 45% of metastatic cases. NRAS mutations occur less frequently (2–7%) but still play a clinically significant role. These mutations lock RAS proteins in an active GTP-bound state, continuously triggering downstream pathways involved in cell division and survival.

BRAF mutations, present in about 10% of CRC patients, also drive carcinogenesis through persistent activation of the MAPK pathway. The most well-known BRAF variant, V600E, is associated with aggressive disease, poor response to therapy, and right-sided colon tumors, especially in female patients. Understanding the mutational landscape of KRAS, NRAS, and BRAF is now standard in CRC management guidelines to inform anti-EGFR therapy eligibility and other targeted treatments.

About the TRUPCR® Colorectal Cancer Mutation Panel Kit

The TRUPCR® Colorectal Cancer Mutation Panel is a robust, CE-IVD certified assay specifically developed to detect multiple hotspot mutations in KRAS, NRAS, and BRAF genes. It covers codons 12, 13, 61, 117, and 146 of RAS, and the clinically significant V600E mutation in BRAF.

All necessary reagents, including internal extraction and amplification controls, are provided in a single kit. The assay requires only standard real-time PCR instrumentation, making it highly accessible to routine clinical labs. Designed for user-friendliness and reliability, the kit offers fast turnaround with minimal hands-on time.

Principle and Workflow

The test follows a straightforward workflow optimized for molecular diagnostics:

1. Sample Preparation – Genomic DNA is extracted from FFPE, fresh, or frozen colorectal tumor tissue.
2. PCR Setup – Reaction mixtures are prepared using the provided mastermix and mutation-specific primers and probes.
3. Real-time PCR Detection – Amplification occurs using allele-specific primers and fluorescent probes that distinguish between wild-type and mutant alleles.
4. Data Analysis – Results are interpreted based on amplification curves and Ct values, with controls validating the assay run.

The assay’s high sensitivity allows for reliable detection of mutations present at low allelic frequencies, enabling early detection of tumor heterogeneity or minimal residual disease.

Clinical Application

Mutation testing for KRAS, NRAS, and BRAF is now an essential part of colorectal cancer diagnostics. Patients with KRAS- or NRAS-positive tumors are typically resistant to anti-EGFR monoclonal antibody therapies such as cetuximab and panitumumab. Detecting these mutations helps clinicians avoid ineffective treatments and consider alternative strategies.

Likewise, identification of BRAF V600E mutations has prognostic significance and can guide the use of combination therapies, including BRAF inhibitors. The TRUPCR® panel supports precise and efficient mutation profiling, enabling molecular stratification and improved therapeutic outcomes for CRC patients.